"The National Elections Commission announces that citizen Armando Emilio Guebuza has been re-elected president of the republic of Mozambique for a period of five years," the commission's chief Joao Leopoldo da Costa told reporters, after the vote on October 28.
In the parliamentary race, Guebuza's Frelimo increased its majority from 160 seats to 191 seats in the 250-member legislature.
The race for second place -- closely watched in the wake of a recent opposition split -- was won by long-time opposition leader Afonso Dhlakama, leader of the former rebel movement Renamo, who took 16.5 percent of the vote.
Daviz Simango, founder of the breakaway Democratic Movement of Mozambique (MDM), was in third place with 8.6 percent. The new party took only eight seats in parliament, against 51 for Renamo.
The October 28 vote was Mozambique's fourth national poll since a 16-year civil war between Renamo and the Frelimo government ended in the establishment of multi-party democracy in 1994.
South African President Jacob Zuma on Wednesday congratulated Guebuza on his re-election, hailing the "excellent, historic and neighbourly relations" between the neighbouring countries and their citizens.
"It is furthermore my profound wish that these warm and close ties will continue to prosper during your new term of office", said Zuma in a statement.